This section provides background information related to the present disclosure which is not necessarily prior art.
A typical automotive engine is a four-cycle internal combustion device which includes an engine block having multiple cylinders. Each cylinder supports a piston for reciprocating movement. A cylinder head is coupled to a top surface of the engine block such that the block, head and piston top define a combustion chamber. The cylinder head includes a set of intake ports and a set of exhaust ports for each cylinder which, in combination with the intake valves and exhaust valves, allow combustion gases to enter the combustion chambers and exhaust gases to exit from the combustion chamber. An intake manifold and an exhaust manifold are typically coupled to the cylinder head for routing the combustion and exhaust gases to and from the intake and exhaust ports.
It is common for a portion of the exhaust gases exiting the combustion chamber to be recirculated through an exhaust gas recirculation or EGR circuit to the intake manifold. While EGR is effective for decreasing undesirable engine emissions under certain driving conditions, it can negatively impact the engine performance including fuel efficiency and power output. These effects can be minimized when the EGR is adequately mixed with intake air and the EGR/air mixture is proportionally distributed to each cylinder of the internal combustion engine. Accordingly, there is a need for an improved EGR-air flow distribution system which can be readily incorporated into existing engine architecture in a cost effective manner.